This invention relates to a sheet material and an envelope for packaging electronic parts.
Such electronic parts as semiconductors, which are vulnerable to static electricity, can be easily damaged by static electrification before and after they are attached to electronic circuits, presenting a serious problem.
Thus, protection of electronic parts from static electricity has heretofore resorted to the use of metal foils and plastic films having electrically conductive materials, such as carbon and metal powders, incorporated therein as packaging materials for electronic parts.
However, these materials, all of which are opaque, as such, do not allow visual inspection to ascertain whether the contents, or electronic parts, are present and whether they are damaged or to ascertain their type. On the other hand, plastic films having antistatic agents incorporated therein are available, but their electric resistance is so high that they are altogether unsuitable for protection of electronic parts, and depending upon the type of the antistatic agent used, they can be easily influenced by humidity, a lack of stability.
An object of the invention is to provide a sheet material for packaging electronic parts, through which the contents or electronic parts can be seen and which is effective to protect electronic parts from static electricity.
Another object of the invention is to provide an envelope for effectively protecting electronic parts.
Other objects and advantages of the invention will be apparent from the following detailed description.